Physicochemical and rheological properties of Tremella fuciformis polysaccharide fractions by ethanol precipitation

Abstract

Four Tremella fuciformis polysaccharides (TPS) fractions named as TPS20, TPS40, TPS60, and TPS80 were obtained by stepwise ethanol precipitation. Their physicochemical and rheological properties were investigated. Results showed TPS60 had the highest contents of polysaccharide (81.12%), protein (0.29%), uronic acid (14.36%), and sulfate (5.92%). Their molecular weights were in a descending order of TPS20, TPS40, TPS60, and TPS80. In a certain range of shear rate, they all presented pseudoplastic fluid and viscosity characteristic at low frequency. Increasing temperature or concentration of salts decreased the viscosity of their solutions. Sucrose concentration less than 6% led to an increasing viscosity of TPS20, TPS40, and TPS60. Both strong acidity and alkalinity could reduce the viscosity of all TPS solutions. TPS80 solution showed the best stability and its viscosity was minimally affected by pH, temperature, salts, and sucrose. These results can provide theoretical references for utilizations of TPS fractions in foods, pharmaceuticals, and cosmetics.

Keywords

• tremella fuciformis polysaccharide fractions
• physicochemical properties
• rheological properties
• ethanol precipitation